´óÏó´«Ã½

Britain has not lost a soldier in Afghanistan since the day after Gordon Brown called the general election - that's more than three weeks.

Yet the fatality on 7 April was the third in a week, and throughout the early part of this year the grim news came frequently, sometimes five times in a week.

The Ministry of Defence has been applying an election "purdah" to journalists' embeds or statements by senior officers about current operations there.

Has it also ordered the troops to limit their activities so as to avoid casualties in this sensitive period?

Senior people deny that explicit orders of this kind have been given. Is that right, or could such a change in the pattern of operations have taken place without it being formally ordered?

Lucky streak?

At first I wondered whether a troop rotation between brigades in Helmand might explain it. But commanders always deny that there is any loss in "effect" when an experienced unit leaves and newcomers arrive.

Indeed it is only fair to observe that a new battalion is often more likely to incur casualties than not.

So has Britain's Task Force Helmand just been lucky since 7 April? The recent period of good fortune could of course be broken at any time, with some family receiving the dread news from uniformed officers at the door.

Luck can undoubtedly play a part in avoiding fatalities - just talk to the soldiers of A Company, 2nd Battalion, The Yorkshire Regiment
They're recently returned from six months in Sangin. The 3 Rifles battle group that A Company was part of lost 30 soldiers, but the company itself lost none. There were certainly in plenty of firefights alongside their 3 Rifles comrades - many put their survival down to luck.

Could good luck really explain the past three-plus weeks across the whole of the British area in Helmand?

Good fortune has certainly played a role, because the soldiers would still need it even if some order to avoid operations that might cause casualties had indeed been given.

Harvest time

Talking to people at a Royal United Services Institute conference on Afghanistan in London today, I did hear an interesting explanation that goes beyond chance.

It is currently the season for harvesting the opium poppy in southern Afghanistan and that usually produces a lull in fighting.

One Nato official confirmed that reports of violent incidents were "down somewhat" across the south of Afghanistan.

Many gunmen take time off from shooting or laying bombs to help in the harvest. With more people working the fields, there's also a greater danger of the insurgents killing villagers at this time with attacks aimed at Nato.

I'm not sure I believe that the poppy harvest entirely explains the lower British fatality rate since there are still circumstances in which patrols could be attacked.

That and good luck though are important ingredients in explaining the current situation.

But I cannot help remembering hearing tell that in the run up to the last British general election, the British Army in Iraq did try to avoid major set piece operations that might lead to a flare up in fighting.

So I'm keeping an open mind about the current situation in Afghanistan.

Back in the late 80s at an Admiralty Board lunch, I received a memorable lesson in the symbolic importance of the Trident missiles system.

I was Defence Correspondent for The Independent at that time, as the admirals - sat resplendent in uniform beneath sumptuous paintings of fighting sail - were stunned into shocked silence by Peter Snow, Newsnight's then presenter and diplomatic editor.

"Trident!", he began, "phallic symbol? Yes? No?"

The First Sea Lord and others looked at Snowy in consternation - it was like one of those Bateman cartoons of a terrible social faux pas. I couldn't stop myself giggling, as Newsnight's dreadnought ploughed on, "huge, towering, virility symbol? Yes? No? What?"

It was only once Peter had thrown them a line by moving away from strictly phallic imagery that the naval chiefs started to form an answer, and the moment passed.

This week's focus on Trident in the foreign affairs debates (of wannabee foreign secretaries on Monday and party leaders tomorrow) has reminded me of Snowy's point: that the debate about Britain's nuclear weapons is (largely) one about symbolism.

There seems to be a received wisdom among many in the Westminister bubble that the Lib Dem's rejection of a 'like for like' replacement of Trident marks them out as hopelessly naive or weak.

Yet I remember not long before the 2006 decision in principle to replace Trident with a similar submarine launched ballistic missile system, one senior admiral telling me that a combination of a couple of extra hunter killer submarines with nuclear armed cruise missiles might actually be a better option for the Royal Navy.

At that point the senior service did not dare hope for a like for like replacement (because of its huge cost) and could see the advantages of having a flexible fleet of 8-10 hunter killers, any of which might be nuclear armed.

But Tony Blair and Gordon Brown opted to replace Trident with the speed and secrecy that have become customary in Britain's nuclear decision making.

Today's comments in the Times by some senior former army officers underline that there is a perfectly respectable defence debate to be had that replacing Trident with a similar system is too expensive and represents overkill shows that Nick Clegg and his party cannot be accused of irresponsibility.

Trident was chosen by a Cabinet committee in 1979 because it satisfied the so-called 'Moscow Criterion', a British government requirement that the national nuclear weapons' system be able to destroy the Soviet Union's capital, despite its anti-missile defences. How relevant is the Moscow Criterion today?

Perhaps the whole problem with cruise missiles tucked away in hunter killer submarines or air launched missiles in bunkers at RAF bases is that they do not constitute that kind of overt national virility symbol so gloriously described by Peter Snow.

The debate is worth having - and at least Trident provides ones area where the electorate is being offered a clear choice.

The signing of a new strategic arms limitation treaty on Thursday is a success for President Barack Obama.

But the interesting thing is how the US is the only power that really feels confident about cutting nuclear weapons, and how that holds back wider progress towards disarmament, non-proliferation, and even, that goal beloved of visionary speech makers, the nuclear free world.

Under the agreement to be signed in Prague today, the US and Russia will each cap their strategic nuclear arsenals at 1,550 warheads.

This new limit in fact simply codifies the shrinking of these forces that has taken place since the last round of superpower arms reductions.

The White House would have been happy for deeper cuts, but the Russians were not.

Russia also maintains substantial stockpiles of so-called tactical nuclear weapons such as artillery shells and air dropped bombs that are not included in the new limits, as well as large amounts of chemical weapons.

Why do they do so when their conventional forces have shrunk to a tiny fraction of their Cold War total?

The answer is simple enough - nuclear weapons are one of the few vestiges of the former Soviet superpower that give the Kremlin an air of international importance.

If that seems contemptible, consider Britain's actions in the light of another of Mr Obama's initiatives, the Nuclear Policy Review announced at the start of this week.

America has just renounced the possible use of nuclear weapons against non-nuclear states that are compliant with the Non Proliferation Treaty.

This removes some of the ambiguity which the Pentagon insisted for decades was essential for nuclear deterrence.

For that reason it is an important move, even if some of the obvious US potential targets such as North Korea or Iran have been explicitly ruled out of the new pledge.

Wouldn't Britain, with its pocket sized nuclear forces, do well to follow suit?

No, according to people I've been speaking to in government. Attempts by Prime Minister Gordon Brown to follow the US Nuclear Policy Review, have been blocked by the Ministry of Defence (MoD), say insiders.

Britain apparently wishes to maintain the "ambiguity" of a posture that includes a possible nuclear strike against Syria or indeed Bolivia, just to pluck some random examples out of the air.

As Britain struggles to finance the replacement of its single remaining nuclear system, Trident, it finds it hard to rule out such bizarre possibilities.

Britain, then is not so different from Russia in wishing to retain the status of a nuclear weapon state, it just uses slightly different arguments, for example about the unpredictability of the modern world.

Whitehall enthusiasts for a British version of the US Nuclear Policy Review had hoped that it might add some small weight to Mr Obama's attempts to halt the proliferation of nuclear weapons more generally.

The MoD's obstruction, apparently added another reason for Mr Brown not to attend next week's nuclear disarmament conference in Washington.

At that conference, Mr Obama will try to use the new treaty with Russia or policy review to strengthen his hand in preventing the proliferation of weapons - Iran is an obvious target of such diplomacy.

But the conference is likely simply to underline a salient truth: that only the US feels big and safe enough to conduct this kind of diplomacy with any real sincerity.

Countries like Pakistan, for reasons best known to themselves, are increasing their nuclear stockpiles despite the threat to the security of those weapons.

Israel remains outside any meaningful supervision in this area.

Iran continues to play its decade-long game of obfuscation with the international community, feeding the impression that it is racing to complete its own atomic arsenal.

While the US tires of the burden and risks of being a nuclear superpower, everyone else it seems wants to buttress their claims to regional or global influence.